Lasers are used in a myriad of industrial, medical, commercial, scientific and military applications. The advent of compact, battery-powered solid-state lasers has led to an interest in developing light-based non-lethal technologies (NLT) for law enforcement and military applications. Laser illuminators, capable of producing non-damaging high-brightness glare sources have applications in suspect apprehension, crowd control, perimeter defense, and intruder delay and denial. For example, laser illuminators provide an unequivocal warning to the adversary that his presence has been detected and may also impede mobility by degrading visual sensitivity. Effectiveness of laser illuminators has been limited by the inability to project sufficient light at a distance (“downrange”) and, at the same time, to be eye safe at close range. Because of safety concerns, the power of lasers used in consumer applications often do not exceed a maximum permissible exposure.
The safety limitation of conventional illuminator designs is inherent in the point source nature of lasers. The conventional laser illuminators as well as common laser pointers emit a nearly collimated or parallel beam of light. When directed towards the human eye, a collimated beam may be focused to a point on the retina by the cornea and lens of the eye. Focusing causes the light energy to become extremely concentrated, greatly increasing the thermal damage potential of the light. The focused light can cause eye as well as skin damage.